i have a 6.5 kw but i believe water pump is the same access impeller by removing 6 screws from brass plate on the rear of water pump impeller is behind plate you can download manaul at http://generator-parts.com/
i have a 1990 350 what happens is searay installed thru hull on one side of stringer and pump on the other side so the hose goes over the stringer when ever boat is pulled this forms an air lock in hose igot tired of repriming every time i pulled for bottem cleaning so i relocated pump to...
im not sure but they they probably are going to cut fairing block for you. i have a 1990 350 and transducer is installed under port side seat in aft cabin as far as i know this was from factory hull is flat at that location and no fairing block was used
if possable bring engine up to operating temp less chance of breaking bolts i have not broken a bolt since useing this method wear gloves also do yourself a favor use new manifold bolts they get weakened and its really a pain when one breaks going back together